linux/arch/m68k/kernel/time.c

112 lines
2.6 KiB
C

/*
* linux/arch/m68k/kernel/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
*
* This file contains the m68k-specific time handling details.
* Most of the stuff is located in the machine specific files.
*
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/irq_regs.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/profile.h>
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "xtime_update()" routine every clocktick
*/
static irqreturn_t timer_interrupt(int irq, void *dummy)
{
xtime_update(1);
update_process_times(user_mode(get_irq_regs()));
profile_tick(CPU_PROFILING);
#ifdef CONFIG_HEARTBEAT
/* use power LED as a heartbeat instead -- much more useful
for debugging -- based on the version for PReP by Cort */
/* acts like an actual heart beat -- ie thump-thump-pause... */
if (mach_heartbeat) {
static unsigned cnt = 0, period = 0, dist = 0;
if (cnt == 0 || cnt == dist)
mach_heartbeat( 1 );
else if (cnt == 7 || cnt == dist+7)
mach_heartbeat( 0 );
if (++cnt > period) {
cnt = 0;
/* The hyperbolic function below modifies the heartbeat period
* length in dependency of the current (5min) load. It goes
* through the points f(0)=126, f(1)=86, f(5)=51,
* f(inf)->30. */
period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
dist = period / 4;
}
}
#endif /* CONFIG_HEARTBEAT */
return IRQ_HANDLED;
}
void read_persistent_clock(struct timespec *ts)
{
struct rtc_time time;
ts->tv_sec = 0;
ts->tv_nsec = 0;
if (mach_hwclk) {
mach_hwclk(0, &time);
if ((time.tm_year += 1900) < 1970)
time.tm_year += 100;
ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
time.tm_hour, time.tm_min, time.tm_sec);
}
}
void __init time_init(void)
{
mach_sched_init(timer_interrupt);
}
#ifdef CONFIG_M68KCLASSIC
u32 arch_gettimeoffset(void)
{
return mach_gettimeoffset() * 1000;
}
static int __init rtc_init(void)
{
struct platform_device *pdev;
if (!mach_hwclk)
return -ENODEV;
pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
return 0;
}
module_init(rtc_init);
#endif /* CONFIG_M68KCLASSIC */